1) Field of the Invention
The present invention relates to a door lock device for a vehicle, and more particularly, to a door lock device that switches from an unlock state to a lock state of a door in response to an operation of an inside lock button.
2) Description of the Related Art
Conventionally, a vehicle, such as four-wheeled vehicle, generally has a door lock device provided between an outside handle disposed for a door and a latch mechanism. The latch mechanism usually has a latch and a ratchet, and is so configured that when a door is closed relative to the vehicle body, the latch hold a striker on the vehicle body side by meshing, and the ratchet keeps the meshing state between the latch and the striker, whereby the door is kept in closed state relative to the vehicle body. The door lock device has a lock mechanism which switches between an unlock state and a lock state in response to a key operation on a key cylinder provided in the door on the interior side or by an operation on an inside lock button provided in the door on the interior side. Linkages between the lock mechanism and the key cylinder, and between the lock mechanism and the inside lock button are respectively accomplished by wire cables (see for example, Japanese Patent Application Laid-Open Publication No. 2001-262905).
The door lock device in an unlock state permits a door-opening operation by the outside handle and transmits it to the ratchet, and when the ratchet engages the latch, the door lock device cancels the engaging state of the ratchet to the latch. As a result, the meshed state between the latch and the striker is also canceled, so that a door-opening operation relative to the vehicle body is enabled.
The door lock device in a lock state disables a door-opening operation by the outside handle to disable transmission to the ratchet. As a result, even when the outside handle is operated, the meshed state between the latch and the striker is kept, to allow locking of the vehicle.
On the other hand, the door lock device in a lock state cancels the lock state and enables a door-opening operation by the inside handle to allow transmission to the ratchet, when a door-opening operation is made with the inside handle, while it serves to cancel this engaged state between the latch and the ratchet when the ratchet engages the latch. As a result, the meshed state between the latch and the striker is also canceled, so that a door-opening operation relative to the vehicle body is enabled.
According to the above door lock device, when the inside lock button is operated for locking, an inner wire of a wire cable is pushed out of an outer tube of the wire cable, and the lock mechanism transits from an unlock state to a lock state. When the inside lock button is operated for unlocking, the inner wire of the wire cable is drawn into the outer tube of the wire cable, and the lock mechanism transits from a lock state to an unlock state.
In the above door lock device, since the lock mechanism transits from a lock state to an unlock state just by drawing in the inner wire of the wire cable, the lock mechanism will transit from a lock state to an unlock state in response to a drawing action exerted on the inner wire of the wire cable, for example, by pulling or pushing the wire cable integrally with the outer tube from outside of a door by suitable means. This is unfavorable in respect of the antitheft ability.